摘要
为明确陆地生态系统中不同演替阶段群落土壤氮素循环对温度响应的变化规律,本研究以不同演替阶段草地、灌丛林、白桦(Betula platyphylla)林、青杄(Picea wilsonii)-白桦林、青杄林群落的土壤为研究对象,采用室内恒温好气培养法,研究不同温度(15、25、35℃)条件下土壤氨化、硝化特征。研究表明:1)土层深度分别对氨化速率、累积氨化量、硝化速率和累积硝化量有极显著影响(P<0.01);随着土层深度的增加,不同演替阶段群落土壤氮素氨化速率与累积氨化量、硝化速率与累积硝化量均呈现降低趋势,其中0-20 cm土层取得最大值。2)演替群落分别对氨化速率、硝化速率有极显著影响(P<0.01)。随着演替的正向进行,除草地群落的0-20 cm土层外,其余演替阶段群落土壤氮素氨化速率呈先降低后升高再降低趋势,其中草地的氨化速率最大;而不同演替阶段群落土壤氮素硝化速率表现为先升高后降低,其中青杄-白桦林的硝化速率最大。3)温度对氨化速率、累积氨化量、硝化速率和累积硝化量有极显著影响(P<0.01);除灌丛林、青杄-白桦林群落的0-20 cm土层、青杄林、白桦林、青杄-白桦林群落的20-40 cm土层、草地群落的40-60 cm土层外,其余演替阶段群落土壤氮素氨化速率与不同演替阶段群落土壤氮素累积氨化量随土壤温度的升高(15~35℃)而增大,其中35℃下最大(154.03 mg·kg^(-1)),而不同演替阶段群落土壤氮素硝化速率和累积硝化量均随温度的上升呈先增加后降低趋势,其中25℃下最大(529.10 mg·kg^(-1))。4)不同演替阶段群落土壤理化性质(全氮、田间持水量、氨态氮、土壤容重)在15和25℃下对土壤氮素氨化、硝化速率均有显著影响(P<0.05)。本研究结果为土壤供氮能力的动态变化和该区域生态系统管理提供理论依据。
Soil from different succession stages(grassland,shrub forest,Betula platyphylla forest,Picea wilsonii-B.platyphylla forest,and P.wilsonii forest)and an indoor constant-temperature aerobic culture method were used to clarify the response of the soil nitrogen cycle to temperature in different succession stages of terrestrial ecosystems.The characteristics of soil ammonification and nitrification under different temperatures(15,25,and 35℃)were studied.The results showed the following.1)Soil depth significantly affected the ammonification rate,cumulative ammonification,nitrification rate,and cumulative nitrification(P<0.01).With an increase in soil depth,the ammonification rate,cumulative ammonification amount,nitrification rate,and cumulative nitrification amount of soil nitrogen in different succession stages showed a decreasing trend,among which those in the 0-20 cm soil layer was the largest.2)Successive communities significantly affected ammonification and nitrification rates(P<0.01).With positive succession,the ammonification rate of soil nitrogen in succession stages other than the 0-20 cm soil layer of the grassland community first decreased,then increased,and then decreased.The ammonification rate of grassland was the highest.The nitrification rate of soil nitrogen at different succession stages first increased and then decreased,and the nitrification rate of P.wilsonii-B.platyphylla forest was the highest.3)Temperature significantly affected ammonification rate,cumulative ammonification amount,nitrification rate,and cumulative nitrification amount(P<0.01).Except for the 0-20 cm soil layer of shrub forest and P.wilsonii-B.platyphylla forest community,the 20-40 cm soil layer of Picea wilsonii forest,Betula platyphylla forest,P.wilsonii-B.platyphylla forest community,and the 40-60 cm soil layer of grassland community,the soil nitrogen ammonification rate and the cumulative ammonification amount of soil nitrogen in different succession stages increased with the increase of soil temperature(15~35℃),and the maximum level(154.03 mg·kg^(-1))was detected at 35℃.In contrast,the soil nitrogen nitrification rate and cumulative nitrification amount in different succession stages increased first and then decreased with the increase of temperature.The maximum level(529.10 mg·kg^(-1))was detected at 25℃.4)Soil physical and chemical properties(TN,field capacity,NH4+-N,and soil bulk density)at different succession stages had significant effects on soil nitrogen ammonification and nitrification rates at 15 and 25℃(P<0.05).The results of this study provide a theoretical basis for dynamic changes in soil nitrogen supply capacity and ecosystem management in this region.
作者
唐维春
刘小娥
苏世平
王昊
马彦东
唐庆童
TANG Weichun;LIU Xiao’e;SU Shiping;WANG Hao;MA Yandong;TANG Qingtong(College of Forestry,Gansu Agricultural University,Lanzhou 730070,Gansu,China)
出处
《草业科学》
北大核心
2025年第5期1101-1117,共17页
Pratacultural Science
基金
甘肃农业大学科技创新基金−青年导师扶持基金项目(GAU-QDFC-2022-17)
干旱荒漠区生态修复过程中林木对“水-温”协同胁迫的响应机制与试验示范研究项目(23YFFA0066)
基于外源ABA作用的红砂抗旱生理及分子响应机制研究项目(32060335)
甘肃省自然科学基金项目(21JR7RA814)。
关键词
温度
演替阶段
土壤氮素氨化特征
土壤氮素硝化特征
甘肃兴隆山
temperature
succession stage
soil nitrogen ammonification characteristics
soil nitrogen nitrification characteristics
Xinglong Mountain,Gansu Province
